This project examines the function of various oral tissues during physiologic aging or during situations in which normal oral functions are altered due to specific diseases or complicating therapeutic procedures. The project focuses on two major oral health problem areas: salivary gland function, and oral motor function. Major efforts have been directed at evaluating sodium handling from the stimulated parotid glands; examining unstimulated and stimulated parotid saliva output in different aged persons; studying the effects of (1) X-irradiation and (2) combined chemotherapy on salivary gland function and oral health; developing procedures to evaluate the oro-pharyngeal phase of swallowing using ultrasonic imaging; and characterizing the nature of complaints, and oral status, in persons with oral dryness (xerostomia).